Imines are important for a variety of applications. For example, imines are intermediates in many reactions of both enzymatic and pharmaceutical interest, making imines quite valuable and useful to a number of various fields. In particular, aryl aldimines are important for synthesis of a number of end products. Such end products include, for example, antibiotics and intermediates in the synthesis of antibiotics. From an environmental standpoint, aryl aldimines may be useful as additives to polymers to increase the rate of degradation of plastics in the environment.
Unfortunately, the formation of imines, such as aryl aldimines, has typically not involved environmentally friendly techniques and components. In addition, the methods used to make such imines are typically costly and involve lengthy reaction times. Traditional syntheses, for example, often involve the use of toxic solvents such as methylene chloride, and/or hazardous processes such as refluxing in petroleum-based solvents such as toluene as azeotroping agents. In one particular method, imines are made through reaction in toluene, which is a non-renewable solvent and is suspected to be teratogenic and mutagenic. Some recent imine syntheses have successfully used solvents or conditions that are more benign, but still require vigorous stirring, heat, recrystallization or other work up procedures, which negate some of the benefits of the green synthesis itself. Further, many of these processes result in a significant amount of waste, which again negates some of the benefits of green synthesis itself.
The present invention seeks to remedy these and other defects by providing a general method that is broadly applicable to a variety of imine syntheses, while also being environmentally friendly, efficient, and cost-sensitive.